diff options
| author | Stefan Agner <stefan@agner.ch> | 2015-01-26 01:10:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-02 10:09:55 -0800 |
| commit | bfc2e07f910891516c8eeef61859fa17369fea9f (patch) | |
| tree | dff78a4eb45e351e013a09253e06debddfcb1a81 /drivers/tty | |
| parent | 2fe605df325abfa2d36f63469fa960cd40d8cf50 (diff) | |
| download | blackbird-obmc-linux-bfc2e07f910891516c8eeef61859fa17369fea9f.tar.gz blackbird-obmc-linux-bfc2e07f910891516c8eeef61859fa17369fea9f.zip | |
tty: serial: fsl_lpuart: terminate DMA on buffer flush
On uart buffer flush, serial core resets the circular buffer.
If a DMA transfer is in progress at that time, the callback
lpuart_dma_tx_complete will move buffer's tail unconditionally,
hence tail moves beyond head. Use the flush_buffer hook to
terminate the DMA imeaditely and avoid lpuart_dma_tx_complete
being called in this situation.
This bug often showed up while shutdown and lead to duplicate
serial console output.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/fsl_lpuart.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index f196a33e619b..b1893f3f88f1 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -455,6 +455,15 @@ static int lpuart_dma_rx(struct lpuart_port *sport) return 0; } +static void lpuart_flush_buffer(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + if (sport->lpuart_dma_tx_use) { + dmaengine_terminate_all(sport->dma_tx_chan); + sport->dma_tx_in_progress = 0; + } +} + static void lpuart_dma_rx_complete(void *arg) { struct lpuart_port *sport = arg; @@ -1496,6 +1505,7 @@ static struct uart_ops lpuart_pops = { .release_port = lpuart_release_port, .config_port = lpuart_config_port, .verify_port = lpuart_verify_port, + .flush_buffer = lpuart_flush_buffer, }; static struct uart_ops lpuart32_pops = { @@ -1514,6 +1524,7 @@ static struct uart_ops lpuart32_pops = { .release_port = lpuart_release_port, .config_port = lpuart_config_port, .verify_port = lpuart_verify_port, + .flush_buffer = lpuart_flush_buffer, }; static struct lpuart_port *lpuart_ports[UART_NR]; |
